284 Reports and Proceedings—Geological Society of London. 
of the Musch Plain, the Malaskert Plain, Lake Van, and the Bingo] 
group. As indicated by its title, Dr. Oswald’s new work is a purely 
tectonic one, and rounds off the story of the geology of a district 
which he has so lucidly and fully described. 
IAQ R ans) VAINYD 22 @CG Sth iNet. 
I.—GuotoetcaL Sociery oF Lonpon. 
April 18, 1910.—Professor W. W. Watts, Se.D., M.Sec., F.R.S., 
President, in the Chair. 
The following communications were read :— 
1. ‘The Voleano of Matavanu in Sava.’ By Tempest Anderson, 
MDL, DiSeu, Gas. 
Savaii is one of the German Samoan Islands in the Central Pacific 
Ocean. It is entirely volcanic, is formed of different varieties of basic 
lavas, and is for the most part fringed with coral reefs. 
The volcano of Matavanu was formed in 1905. The eruption was 
at first explosive, but since the first few weeks has been mainly 
efflusive and accompanied by the discharge of an enormous volume of 
very fiuid basic lava, which has run by a devious course of about 
10 miles to the sea, formed extensive fields of both slaggy and cindery 
lava (pahoehoe and aa), filled up a valley to a depth in some places of 
probably 400 feet, and devastated some of the most fertile land in the 
island. ‘The crater contains a lake, or rather river, of incandescent 
lava, so fluid that it beats in waves on the walls, rises in fountains of 
liquid basalt, and flows with the velocity of a cataract into a gulf or 
tunnel at one end of the crater. It then runs underground along 
a channel or channels in the new lava-field until it reaches the sea, 
into which it flows, and causes explosions attended with the discharge 
of showers of sand and fragments of hot lava, and the emission of vast 
clouds of steam. 
The many resemblances to, and few differences from, the voleano of 
Kilauea are discussed. 
2. ‘Notes on the Geology of the District around Llansawel 
(Carmarthenshire).” By Miss Helen Drew, M.A., and Miss Ida 
L. Slater, BA. (Communicated by Dr. J. E. Marr, F.R.S., F.G.S.) 
In this paper the authors deal with the stratigraphy and geological 
structure of a small area some 9 miles to the west of Llandovery, and 
to the north of Llandeilo. In a brief introduction the reasons for the 
selection of this region are mentioned, and the work of previous 
observers is touched upon. 
The rocks consist of a varied series of sediments, including a coarse 
conglomerate, grits, shales, and tough blue mudstones; cleavage is 
almost everywhere intense. 
The beds fall naturally into three divisions, as follows :— 
( ( C 3. Pengelli Shales (Gala fauna). 
C. Luansawet Group { C 2. Zone of Monograptus communis. 
C 1. Clyn March or cyphus Grits and Shales. 
( B 2. Llathige Shales and Mudstones. Zone of Meso- 
5: graptus modestus. 
| B 1. Penn-y-ddinas Grits and Shon Nicholas Conglomerat:. 
A. Brrtt Tew Grove. Beili Tew Grits and Shales. 
B. Caro Group 
